Simultaneous determination of ascorbic acid and NADH in pharmaceutical and biological samples using voltammetric sensor

Vitamins play significant roles in human bodily functions such as immunity, metabolism and digestion. According to experts, vitamin C is one of the safest and most effective nutrients in food science. Most of the studies shows used 500 daily milligrams of vitamin C is necessary to achieve health results. Therefore, it is very important for determination of vitamin C in food samples. Nicotin amide adenine dinucleotide (NADH) is an important coenzyme and plays a key and virtual role in energy metabolism by accepting and donating electrons. On the other hand, NADH oxidation in ocular tissues can be effective on the presence of ascorbic acid [1]. So, determination of the above compounds is very important in biological, food and pharmaceutical samples. A high sensitive sensor based on carbon paste electrode modified with CdO nanoparticle and 1-methyl-3-butylimidazolium bromide was used for the voltammetric analysisof vitamin C in the presence of nicotin amide adenine dinucleotide. The high sensitive sensorshows excellent enhancement and electrocatalytic activity towards vitamin C. The variation ofpH shows the number of proton is equal to number of electron for vitamin C electrooxidation. The electro-oxidation peaks current of vitamin C and nicotin amide adenine dinucleotideincreased linearly with their concentration in the ranges of 0.07–480 μmol L-1 vitamin C and 0.5–700 μmol L-1 nicotin amide adenine dinucleotide. The limit of detection for vitamin C andnicotin amide adenine dinucleotide were 0.03 μmol L-1 and 0.1 μmol L-1, respectively. Simultaneous determination of vitamin C and nicotin amide adenine dinucleotide was investigated by using square wave voltametry technique. The proposed sensor showed goodstability, sensitivity, selectivity, reproducibility and can be used for some important food samples analysis.

Keywords:

Ascorbic acid , NADH , Ionic liquids , Voltammetric analysis